Other Common Names
Striped Sod Webworm (larva)
Synonyms and other taxonomic changes
Fissicrambus mutabilis (Clemens, 1860)
Crambus mutabilis Clemens, 1860
Synonym: Crambus fuscicostellus Zeller, 1863
Explanation of Names
MUTABILIS: a Latin word meaning changeable, from "mutare" (to change); this explains the origin of the common name Changeable Grass-veneer, but I don't know what it refers to - and whether it applies to the adult or the larva
Adult: forewing yellowish-brown with diffuse grayish-white streak running lengthwise in upper half of wing (i.e. nearest the costa); subterminal line black, evenly toothed; PM line jagged, irregularly toothed, sometimes continuous but often broken and represented by just two or three black spots; hindwing variably pale to dark brownish-gray
Larva: presumably striped (considering the common name of Striped Sod Webworm) but no specific descriptions were found on the Internet; general decription of a webworm larva includes a dark head and pale yellow to grayish body with dark spots
Heppner (2003) reported the range to include New York to Florida, Illinois to Texas. (1)
McAlpine et al (2010) includes Prince Edward Island to Quebec.(2)
Lawns, golf courses, grassy areas; adults may be flushed from grass during the day but are crepuscular/nocturnal and come to light.
The main flight period is April to September. (3)
Heppner (2003) reported adults January to December in Florida. (1)
The larvae feed on grasses at night.
Two generations per year; overwinters as a partly-grown larva.
Beadle & Leckie (2012) stated the adults "Rests in a headstand position." (4)
There are many publications online concerning the pest status of turf management.
) forewing has dark speckling in lower half, and lacks a grayish-white longitudinal streak in upper half
) forewing is darker, and lacks a grayish-white longitudinal streak
Bluegrass Webworm Moth
) forewing has a smooth and mostly straight subterminal line, not evenly toothed
pinned adult image
(Larry Line, Maryland)
biology and control
of several webworm species, including F. mutabilis
(Ohio State U.)